Most people have a hard enough time envisioning retirement at all, much less early retirement. Despite that, many workers have managed to quit their jobs and achieve financial independence by age 40 or even younger. Sipping drinks on the beach all...

Among some other interesting findings, there’s this very true warning:
“The very prospect of an early retirement itself may sap the worker’s motivation,” Brian told us. “Why take on difficult projects and learn new skills if you are fifty, but are leaving the workforce in five years?” In other words, the mental retirement effect may kick in before you’ve even left your job.

I guess it must be difficult anyway to maintain similar level of motivation on FIRE. The awareness of being FI makes you more relaxed about work and decreases motivation. You probably have to find something that you love and drives you to wake up in the morning and keep being active.